Resource capacity at lvl 1 is 7.5k
My understanding is that upgrading each minute between 15min-30min should be 1.8k a minute not 7.5k
My understanding is that upgrading each minute between 15min-30min should be 1.8k a minute not 7.5k
I think the Capacity cost scales with the Current Level of your Kingdom.
For me from 30 to 31 minutes is 28k so the 7.5 is normal when at kt5 or higher
As FranKen stated, the cost to upgrade storage time is based on your current base bronze production and scale with it.
Upgrading your kingdom tower sublevel increase both your bronze production AND bronze cost for upgrade storages